MEXICO CITY – Scientists have discovered that dinosaurs may have died out 300,000 years after a giant meteor struck Earth.

MEXICO CITY – Scientists have discovered that dinosaurs may have died out 300,000 years after a giant meteor struck Earth.

It has long been theorized that a meteor strike caused the mass extinction of dinosaurs from our planet. It would not have been the actual impact, but rather the effects that would have killed them off: massive tsunamis, earthquakes, volcanic eruptions and a clouded atmosphere that would have altered the climate.

The proposed site for the meteor strike was the Chicxlub Crater, found on the Yucatan peninsula of Mexico. The crater is 112 miles across and thought to have been created 65 million years ago. It was thought to be the culprit in the extinction of 65 percent of all life on Earth at the time of its arrival.

But now scientists believe that, after further excavation, the meteor did not cause the mass extinction, also known as the Cretaceous–Tertiary extinction event. They have found that sediments linked to the extinction were deposited above the sediments from the time of the asteroid impact.

Gerta Keller, a professor of Geosciences at Princeton University, said, “We found that not a single species went extinct as a result of the Chicxulub impact. These are astonishing results.”

Scientists are now turning to massive volcanic eruptions as the cause. The formation of the Deccan Traps in India, one of the largest volcanic features on the planet, has long been considered a potential suspect. Ash and gases would have blocked out sunlight, causing climatic changes and hindering photosynthesis in all plant life, breaking the food chain.

It will be difficult to break away from the meteor theory, however. Meteor defenders will say the sedimentary record merely shifted due to the massive earthquakes and tsunamis that came after. “The impact-kill theory is beautiful in its simplicity,” Keller said. In contrast, “the ground truth, the data that supports the impact and at the same time refutes the theory, is messy and complicated by normal geological processes.”